Chronic Chagas disease cardiomyopathy, caused by Trypanosoma cruzi infection, is a major cause of heart failure in Latin America. Galectin-3 (Gal-3) has been linked to cardiac remodeling and poor prognosis in heart failure of different etiologies. Herein, we investigated the involvement of Gal-3 in the disease pathogenesis and its role as a target for disease intervention. Gal-3 expression in mouse hearts was evaluated during T. cruzi infection by confocal microscopy and flow cytometry analysis, showing a high expression in macrophages, T cells, and fibroblasts. In vitro studies using Gal-3 knockdown in cardiac fibroblasts demonstrated that Gal-3 regulates cell survival, proliferation, and type I collagen synthesis. In vivo blockade of Gal-3 with N-acetyl-d-lactosamine in T. cruzi-infected mice led to a significant reduction of cardiac fibrosis and inflammation in the heart. Moreover, a modulation in the expression of proinflammatory genes in the heart was observed. Finally, histological analysis in human heart samples obtained from subjects with Chagas disease who underwent heart transplantation showed the expression of Gal-3 in areas of inflammation, similar to the mouse model. Our results indicate that Gal-3 plays a role in the pathogenesis of experimental chronic Chagas disease, favoring inflammation and fibrogenesis. Moreover, by demonstrating Gal-3 expression in human hearts, our finding reinforces that this protein could be a novel target for drug development for Chagas cardiomyopathy.

Therapies based on transplantation of mesenchymal stromal cells (MSC) hold promise for the management of inflammatory disorders. In chronic Chagas disease cardiomyopathy (CCC), caused by chronic infection with Trypanosoma cruzi, the exacerbated immune response plays a critical pathophysiological role and can be modulated by MSC. Here, we investigated the role of galectin-3 (Gal-3), a beta-galactoside-binding lectin with several actions on immune responses and repair process, on the immunomodulatory potential of MSC. Gal-3 knockdown in MSC did not affect the immunophenotype or differentiation potential. However, Gal-3 knockdown MSC showed decreased proliferation, survival, and migration. Additionally, when injected intraperitoneally into mice with CCC, Gal-3 knockdown MSC showed impaired migration in vivo. Transplantation of control MSC into mice with CCC caused a suppression of cardiac inflammation and fibrosis, reducing expression levels of CD45, TNFα, IL-1β, IL-6, IFNγ, and type I collagen. In contrast, Gal-3 knockdown MSC were unable to suppress the immune response or collagen synthesis in the hearts of mice with CCC. Finally, infection with T. cruzi demonstrated parasite survival in wild-type but not in Gal-3 knockdown MSC. These findings demonstrate that Gal-3 plays a critical role in MSC survival, proliferation, migration, and therapeutic potential in CCC.

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Mesenchymal stem cells (MSC) are promising tools in the fields of cell therapy and regenerative medicine. In addition to their differentiation potential, MSC have the ability to secrete bioactive molecules that stimulate tissue regeneration. Thus, the overexpression of cytokines and growth factors may enhance the therapeutic effects of MSC. Here we generated and characterized mouse bone marrow MSC lines overexpressing hG-CSF or hIGF-1. MSC lines overexpressing hG-CSF or hIGF-1 were generated through lentiviral vector mediated gene transfer. The expression of hG-CSF or hIGF-1 genes in the clones produced was quantified by qRT-PCR, and the proteins were detected in the cell supernatants by ELISA. The cell lines displayed cell surface markers and differentiation potential into adipocytes, osteocytes and chondrocytes similar to the control MSC cell lines, indicating the conservation of their phenotype even after genetic modification. IGF-1 and G-CSF transgenic cells maintained immunosuppressive activity. Finally, we performed a comparative gene expression analysis by qRT-PCR array in the cell lines expressing hIGF-1 and hG-CSF when compared to the control cells. Our results demonstrate that the cell lines generated may be useful tools for cell therapy and are suitable for testing in disease models.

The COVID-19 pandemic, caused by the rapid global spread of the novel coronavirus (SARS-CoV-2), has caused healthcare systems to collapse and led to hundreds of thousands of deaths. The clinical spectrum of COVID-19 is not only limited to local pneumonia but also represents multiple organ involvement, with potential for systemic complications. One year after the pandemic, pathophysiological knowledge has evolved, and many therapeutic advances have occurred, but mortality rates are still elevated in severe/critical COVID-19 cases. Mesenchymal stromal cells (MSCs) can exert immunomodulatory, antiviral, and pro-regenerative paracrine/endocrine actions and are therefore promising candidates for MSC-based therapies. In this review, we discuss the rationale for MSC-based therapies based on currently available preclinical and clinical evidence of safety, potential efficacy, and mechanisms of action. Finally, we present a critical analysis of the risks, limitations, challenges, and opportunities that place MSC-based products as a therapeutic strategy that may complement the current arsenal against COVID-19 and reduce the pandemic’s unmet medical needs.

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Background: The patients with coronavirus disease 2019 (COVID-19) associated with severe acute respiratory distress syndrome (ARDS) may require prolonged mechanical ventilation which often results in lung fibrosis, thus worsening the prognosis and increasing fatality rates. A mesenchymal stromal cell (MSC) therapy may decrease lung inflammation and accelerate recovery in COVID-19. In this context, some studies have reported the effects of MSC therapy for patients not requiring invasive ventilation or during the first hours of tracheal intubation. However, this is the first case report presenting the reduction of not only lung inflammation but also lung fibrosis in a critically ill long-term mechanically ventilated patient with COVID-19.Case Presentation: This is a case report of a 30-year-old male patient with COVID-19 under invasive mechanical ventilation for 14 days in the intensive care unit (ICU), who presented progressive clinical deterioration associated with lung fibrosis. The symptoms onset was 35 days before MSC therapy. The patient was treated with allogenic human umbilical-cord derived MSCs [5 × 107 (2 doses 2 days interval)]. No serious adverse events were observed during and after MSC administration. After MSC therapy, PaO2/FiO2 ratio increased, the need for vasoactive drugs reduced, chest CT scan imaging, which initially showed signs of bilateral and peripheral ground-glass, as well as consolidation and fibrosis, improved, and the systemic mediators associated with inflammation decreased. Modulation of the different cell populations in peripheral blood was also observed, such as a reduction in inflammatory monocytes and an increase in the frequency of patrolling monocytes, CD4+ lymphocytes, and type 2 classical dendritic cells (cDC2). The patient was discharged 13 days after the cell therapy.Conclusions: Mesenchymal stromal cell therapy may be a promising option in critically ill patients with COVID-19 presenting both severe lung inflammation and fibrosis. Further clinical trials could better assess the efficacy of MSC therapy in critically ill patients with COVID-19 with lung fibrosis associated with long-term mechanical ventilation.